1error[E0596]: cannot borrow `foo` as mutable, as it is not declared as mutable
2  --> $DIR/span-covering-argument-1.rs:5:14
3   |
4LL |             let $s = 0;
5   |                 -- help: consider changing this to be mutable: `mut foo`
6LL |             *&mut $s = 0;
7   |              ^^^^^^^ cannot borrow as mutable
8...
9LL |     bad!(foo whatever);
10   |     ------------------ in this macro invocation
11   |
12   = note: this error originates in the macro `bad` (in Nightly builds, run with -Z macro-backtrace for more info)
13
14error: aborting due to previous error
15
16For more information about this error, try `rustc --explain E0596`.
17